MICROBIAL GROWTH IN A MIXED CULTURE

Microbial growth in a mixed culture is key in microbial ecology, food microbiology, epidemiology, and evolutionary microbiology. However, good methods for predicting growth in a mixed culture are lacking.

We are developing and testing a general method for predicting and interpreting growth in a mixed culture. Population growth models are fitted to data from growth curve experiments in which the densities of two microbial strains are measured when grown separately and together. The estimated growth parameters, which capture complex growth dynamics, are then used to predict the growth of the strains in a mixed culture.

We are testing our method using competition experiments with bacteria or yeast.

Our new method has several interesting applications, including inference and interpretation of fitness from growth curve data, and detection of frequency-dependent interactions between different microbial strains.